Refining petroleum oils



April 27, 1943. A. P. HEWLETT ErAL.

REFINING PETROLEUM CIL 'III-II' LZ v. n 95. tw K D IN NOLIN mu NeR N NR.NGL (Nntq Filed Jan. 3, 1940 www! 0L EQ Qu QQ R EO uNm...

Nub Gi Patented Apr. 27., 1943 i REFININ G PETROLEUM OILS Amiot P.Hewlett, Summit, and Gerald E. Phillips,

Cranford, N. J., assitnors to Standard Oil Development Company, acorporation of Dela- Application January 3, 1940,'Serial No. 312,198

11 Claims.

The present invention relates to a process for the refining oi petroleumoils. The invention is particularly concerned with a process for theproduction of improved motor fuels having high anti-knockingcharacteristics as measured by a high octane number, which comprisesbauxite treating feed oils of particular characteristics. In accordancewith the present invention, petroleum oils are processed underconditions adapted to produce products boiling in the motor fuel boilingrange and characterized by having high acid heats and relatively lowclear octane numbers. These oils are then contacted with bauxite undersuitable conditions to produce high quality motor fuels.

It is known in the art to desulfurize petroleum oils by contacting feedoils with bauxite at elevated temperatures by various processes. Forexample, it is known to remove objectionable sulfur compounds fromvirgin feed oils by contacting the same with bauxite at temperatures inthe range of about 600 F. to 650 F. It is also known to treatdistillates boiling in the motor fuel boiling range secured from variouscracking operations with bauxite at temperatures in the range from about600 F. to 800 F. In these operations, the oils which are bauxite treatedhave been previously processed in a manner to secure a product havingthe highest clear octane number. Thus, for example, it is known tobauxite treat petroleum oils which have been cracked under conditionsadapted to produce cracked products having relatively high octanenumbers and having relatively low acid heats. We have now discoveredthat unexpected desirable advantages are secured providing the characterof the feed oils is controlled so that the bauxite not only functions asa desuliuriza-l tion agent, but also functions in a manner to T. M.) arebauxite treated at optimum temperature and pressure conditions.

I'he process of our invention may be readily understood by reference tothe attached drawing illustrating one modification of the same. For thepurpose of illustration it is assumed that the feed oil of thischaracter is produced by a thermal cracking operation. Feed oil isintroduced into primary bubble tower I by means of fresh feed line 2.For purposes of illustration it is assumed that the feed oil is a gasoil boiling in the range from about 400 F. to 700 F. The feed oil iswithdrawn along with recycle oil from the bottom of preliminary bubbletower I by means of line 3 and introduced into heating coil 4. Heatingcoil 4 comprises suitable convection and radiant sections. The oil ispassed through heating coil 4 andraised to the desired crackingtemperatures. The heated oil, under cracking temperatures, is withdrawnfrom heating coil 4 by means of line 5 and passed into reaction chamberor soaking drum 6 in which the oil is'maintained for the desired timeperiod under conditions adapted to control the cracking operation. Theoil is withdrawn from reaction chamber 6 by means of line 1, passedthrough pressure release valve 8, and then flashed in tar separator 9from which substantially all the oil is removed overhead by means ofline II as a vapor. Tarry materials are withdrawn from separator 9 bymeans of line I0 and removed from the system. The overhead vapors fromseparator l0 are introduced into primary bubble tower I. Temperature andpressure conditions are maintained on bubble tower I adapted to separatea cycle oil which is removed wth the fresh feed by means of line 3 and-to remove overhead by means of line I2 a distillate product of thedesired endpoint. The overheadproduct from bubble tower I is kintroducedinto secondary bubble tower I3. Temperature and pressure conditions ontower I3 are similarly adapted to segregate a heating oil or equivalentfraction which is withdrawn from the bottom of the tower by means ofline I4 and removed from the system. An overhead product of the desiredendpoint, preferably in the range from about 400 F. to 420 F.. isremoved by means of line I and bauxite treated as desired. The overheadfraction removed from tower I3 by means of line I5 may be heated inheater I6 prior to contacting the overhead with bauxite in bauxitetreating unit I'I. The bauxite treated oil is withdrawn from bauxitetreating unit I'I and preferably passed through clay contacting unit I9.The clay contacted oil is withdrawn from clay contacting unit I9, passedthrough cooler and then introduced into distillate drum 2i Condenseddistillate is withdrawn from distillate drum 2I by means of line- 25,while overhead vapors are removed by means of line 22.

The process of the present invention may be widely varied. Under certainconditions it may be desirable to condense the overhead distillate incondenser 21 and to pass the condensed distillate into distillate drum28. The condensed distillate is removed from drum 28 by means of line30, passed through heating unit I6, bauxite treating unit I1 and theclay contacting unit I9 as described. Uncondensed gases are removed fromdrum 28 by means of line 29. With certain feed oils the bauxite treatedproduct may bypass the clay contacting plant by means of line 3l. Gasesmay be recycled with the fresh feed from the respective drums 28 and 2|by means of line 24. These gases may be heated inheater 32. Gases fromthe respective distillate drums likewise may be recycled with the feedto the bauxite treating unit by means of line 26.

The feed oils passed to the bauxite treating unit in accordance with theprocess of the present invention are cracked petroleum oils having acidheats in the range of above about 150 (A. S. T. M.) and clear octanenumbers in the range below about 70 as determined by the A. S. T. M.method. In general, the feed oils are those oils which have acid heatsin the range above about 225 and clear octane numbers below about 65.

'Especially preferred oils are cracked petroleumV oils having acid heatsin the range above about 260 and clear octane numbers in the range belowabout 62. These oils may be secured in any desirable manner. However, apreferred source of feed oils of this character is from controlledthermal cracking operations in which modied cracking conditions areemployed and in which a maximumoctane number is not secured in thecracked product. Cracking conditions are, in general, adapted to produceoils having high acid heats and having relatively intermediate or lowoctane numbers.

The cracking operations will be a function, to some extent, of theparticular feed oil being processed. In general, the cracking conditionsbest suited for the production'of cracked oils of relatively high acidheats and intermediate octane numbers are relatively mild crackingoperations in which the coil outlet temperatures employed are in therange belowabout 930 F. and the pressures employed are in the rangebelow about 500 pounds per square inch. In general, it is preferred thatthe feed oils for the -bauxite treating unit be cracked distillatessecured from cracking operations in which the feed oils are gas oilsboiling in the range from about 400 F. to 700 F., which cracking coilfeed oils are cracked at temperatures in the range below 900 F. and atpressures below about 300 pounds per square inch. 'I'he distillate oilsof this character are bauxite treated at any desirable temperatures orpressures. However, in general, it is preferred that the oils becontacted with bauxite at a temperature in the range from about 600 F.to 900 F., preferably bauxite treated at a temperature in the range fromabove about 800 F., as for example at a temperature of from 810 F. to820 F. The pressure in the bauxite treating unit may vary widely.Although atmospheric pressure may be employed, elevated pressures aredesirable. Preferred pressures are in the range above about 100 lbs. persquare inch, preferably-in the range of about 300 to 450 lbs. per squareinch and higher.

In order to further illustrate the invention, the following examples aregiven which should not be construed as limiting the same in any mannerwhatsoever.

Example 1 Various operations were conducted in which gas oils boiling inthe range from about 400 F. to 700 F. were thermally cracked undervarious temperature and pressure conditions. The operating conditions,as well as the acid heats and the base octane numbers of the crackeddistillates were as follows:

Table 1 Gas oil cracking conditions Base m r n fqlo' 1Pressure A BTM' A.B.T M

outlet bs./sq. in.

Operation A 875 300 operation Bm-. 93o 300 ig gl Operation 0..... 851300 204 66. 5 Operation D 900 300 180 60 5 operation E 875 125 17e 651e905 1,000 100 64. 6 915 1, 000 100 65.0 905 1,000 86 65. 7 I 850 2, 00070 55. 1 Operation J' 880' 2, 000 88 59. 2 Operation K- 910 2, 000 82 64l operation 915 750 9o calo The octane number improvements of the abovedistillates by bauxite treating at 800 F. to 820 F. are as follows:

From the above data it is apparent that the cracked distillates producedby operations A to E, inclusive, were materially more susceptible tooctane number improvement by bauxite treatment than stocks produced byoperations F to L, inclusive, and that an apparent critical differ- Aence exists.

Table 3 Opera- Opera- Opera- Opera- Operation M tion N tion O tion Ption Q Base octane number 66 6 67.8 70.7 04.2 61.3 Acid heat 294 243 293154 238 Treated octane number 76.1 76 1 75. 9 69. 2 70. 4 Improvement 9.5 8. 3 5.2 5.0 9. 1

Operation M Operation N Operation 0- Inspections Inspections InspectionsTreated t Treated Treated Feed stock Feed stock Feed stock Per centsulfur. 0. 046 0.025 0.030 0.023 0.031 0.019 8.5 28 0 28 -9 2T Gravity..56. 6 57. 3 61. 6 61. 3 60. 4 60. 0 Naphtha distilled (Eugler):

I nitial boiling point. 84 F 89 F. 81 F. 81 F 88 F. 91 F Per centdistilled atl58 F-. 15. 0 14. 0 22. 0 21. 0 20. 5 19. 0 212 F 34.0 35. 038.0 38. 5 40.0 40. i 2577 F-. 52. 5 55. 0 52. 5 54. 0 56. 5 58. i)Final boiling point- 403 F. 390 F. 403 F. 392 F 401 F. 304 F OperationP- Operation Q- lnspections Inspections Treated Treated Feed stock Feedstock 0. 034 0.025 0. 042 0. 032 -ll 3U -9 +30 Gravity 60. 60. 7 61.060.4 Naphtha Distilled (Engler):

Initial boiling point-. 90 1 09 F. 93 F. 100 F. Per cent distilled 158F..- 10.0 14.5 15.0 13.0 212 F. 33.5 33.0 31.0 31.() 257 F 8. 5 49. 545. 5 42. 5 Final boiling point... 400 l* 392 F. 405 F. 400 l".

Further operations were conducted on additional cracked distillate oilswith the following results:

Table 4 Operation B. Operation S Base octane number. 49. 7 05. 2 Acidheat 30 70. 0

Treated octane number 53. 9 67. 1 improvement 4. 2 1. 9

Treated Treated ned stock Feed stock 0. 050 0. 026 0.037 0. 019 7 27 2l30 Gravity 43. 2 43. 2 61. 8 61.8 N laphtha distilled (Eng- Initialboiling point.. 252 l". 144 F 90 F 00 F. l'cr cent distilled atl5i4 F1B. 5 18.0 37. 0 38. 0 00. 0 00. 0 302 .0 77. 0 Final boiling point...399 F 305 F.

The process of the present invention. is not to be limited by any theoryor mode of operation, but only in and by the following claims in whichit is desired to claim all novelty in so i'ar as the prior art permits.

We claim:

1. Process for the production of motor fuels having high anti-knockingcharacteristics comprising contacting petroleum feed oils characterizedby having an acid heat above about 150 and a. clear octane number belowabout 70 with bauxite at a temperature in the range from about 800 F. to850 F.

2. Process in accordance with claim 1 in which said temperature is inthe range from about 810 F. to 820 F.

3. Process in accordance with claim 1 in which said petroleum oils haveacid heats in the range above about 225 and clear octane numbers belowabout 65.

4. Process in accordance with claim 1 in which said petroleum oils haveacid heats in the range above about 260 and clear octane numbers in therange below about 62.

5. Process for the production of high quality motor fuels having highanti-knocking characteristics which comprises subjecting feed petroleumoils to cracking temperatures and pressures adapted to producedistillates boiling in the motor fuel boiling range having acid heats inthe range above about 150 and clear octane numbers in the range belowabout 70, treating said oils with bauxite at a temperature in the rangefrom about 810 F. to 820 F.

6. Process in accordance with claim 5 in which said cracking temperatureis in the range from about 800 F. to 850 F.

7. Process in accordance with claim 5 in which said feed oil is a gasoil boiling in the range from about 400 F. to 700 F. and said crackingtemperatures are below about 900 F. coil outlet and said crackingpressures are below about 300 pounds per square inch.

8. Process in accordance with claim 5 in which said feed oil is a gasoil boiling in the range from about 400 F. to 700 F. and said crackingtemperatures are below about 875 F. and said cracking pressures arebelow about 125 pounds per square inch.

9. Improved process for the production of motor fuels having highanti-knock characteristics comprising subjecting a feed oil boiling inthe range from about 400 F. to 700 F. to a cracking temperature belowabout 930 F. and a cracking pressure below about 300 lbs/sq. in.,whereby a motor fuel having an A. S. T. M. octane number below about 70and an A. S. T. M. acid heat above about 150, and boiling in the rangefrom about F. to 400 F. is produced, segregating said motor fuel andcontacting the same with bauxite at a temperature in the range fromabout 800 F. to 850 F.

10. Process as defined by claim 9 in which said temperature at which themotor fuel is contacted with bauxite is in the range from about 810 F.to 820 F.

l1. Improved process for the production of motor fuels having highanti-knock characteristics comprising subjecting a feed oil boiling inthe range from about 400 F. to 700 F. to a cracking temperature belowabout 850 F. and a cracking pressure below about 300 lbs./sq. in.,whereby a motor fuel having an A. S. T. M. octane number below about 67and an A. S. T. M. acid heat above about 200, and boiling in the rangefrom about 100 F. to 400 F. is produced, segregating said motor fuel andcontacting the same with bauxite at a temperature in the range fromabout 800 F. to 850 F.

AMIOT P. HEWLETT.

GERALD E. PHILLIPS.

